The invention generally relates to methods for tibial nail insertion. In particular, the invention relates to a method for implanting a longitudinal intramedullary nail into a tibia.
Tibial nailing often requires intensive hammering during insertion which might cause iatrogenic fractures.
Getting the rotation correct after intramedullary nailing is a clinical challenge, especially for the femur. However, tibial malrotation after intramedullary nailing is likely more common than reported. The cases of three patients who incurred symptomatic rotational deformities after closed intramedullary nailing are reported in Kevin M. Kahn, MD, et al. “Malrotation after locked intramedullary tibial nailing: Three case reports and review of the literature” (The Journal of TRAUMA, Vol. 53, Number 3, pages 549 to 552). Today, the rotation of a fractured tibia is compared to its non-fractured counterpart, respectively. The rotation is generally evaluated measuring the difference in torsion. The range of acceptable malrotation may be less than 15 degrees.
However, the shape of the tibia is unique. The tibia may have a rotational mismatch between its proximal and distal ends and the ankle joint is externally rotated relative to the proximal part of the tibia (Hideki Mizu-uchi et al. “The effect of ankle rotation on cutting of the tibia in total knee arthroplasty” (The Journal of Bone & Joint Surgery 2006;88:2632-2636)).
For a better understanding, it is noted that the proximal end of the bone is the end of the bone being oriented toward the heart of the human body. The distal end of the bone is the end of the bone being oriented away from the heart of the human body. An intramedullary nail may be a tibia nail, wherein the intramedullary nail comprises a non-driving end and a driving end. The non-driving end is the end of the nail which firstly enters the intramedullary channel of a bone. Entering a bone from the proximal end of the bone is denoted as antegrade entering. Entering a bone from the distal end of the bone is denoted as retrograde entering. Consequently, a nail adapted to be implanted from the proximal end of the tibia may be denoted as antegrade tibial nail.
A tuberositas tibiae plane is a plane defined by the tuberositas tibiae, i.e. the tip most protruding to the front at the proximal end of the tibia, the entry point into the medullary channel and the axis of the medullary channel inside the tibia. Furthermore, the sagittal plane related to the tibia means a vertical plane orientated from the front to the back (anteroposterior) in a natural position of the leg relative to the chest of a human, for example when the lower leg is tensionlessly placed on a table surface with the toes orientated upwardly. Accordingly, the tuberositas tibiae plane is slightly inclined, i.e. externally rotated approximately between 13 degrees and 37 degrees relative to the sagittal plane.